Power distribution boxes (PDB's) are used in various electric and electronic systems, including passenger and commercial vehicles, where they are commonly used as fuse boxes. A PDB may consist of a number of different components such as a lower cover, a busbar and a frame, and may be assembled using a “top-down” or “bottom-up” method. Examples of PDB's using these assembly methods are described, for example, in the U.S. Pat. No. 7,371,080 issued to Masters et al. on 13 May 2008, which is hereby incorporated herein by reference. As described in Masters et al. the addition of a separate protector plate to separate wires from the electrically conducting surfaces of the busbar complicates assembly of the PDB.
In addition, a separately molded protector plate requires retaining features so that it can be attached to a lower cover, and additional retaining features so that it can be attached to the frame. Depending on the particular application for the PDB, it may need to meet certain structural strength requirements. Because the protector plate is a separate piece, it does not contribute significantly to the strength of the lower cover, and the lower cover may need to be constructed with a number of structural reinforcements. Therefore, a need exists for a PDB wherein a protector plate does not need to be separately assembled to a lower cover or frame, thereby eliminating the need for an assembly step, and eliminating separate retaining features provided on the mating components. A need also exists for a PDB having a protector plate that can add structural integrity to a lower cover, thereby helping to eliminate additional structural support members, leading to reduced overall weight and wall thickness for the lower cover.